An air handler is a crucial component of a heating, ventilation, and air conditioning (HVAC) system. Its primary function is to circulate and regulate air within a building. It works by drawing in air, filtering it, and then distributing it through ducts to maintain a comfortable indoor environment. Typically, an air handler contains a blower, heating and cooling elements, and filters. The blower moves the air, while the filters remove dust and allergens, ensuring cleaner air. Air handlers can be used in both residential and commercial settings, often working in conjunction with other systems like furnaces and air conditioners.